Tire-vulcanizing apparatus.



J. D. TEW.

TIRE VULCANIZING APPARATUS. APPLICATION FILED Aue.9. 1'913.

" s; Patented Apr. 27, 1915.

JAMES D.TEW, OF AKRON, OHIO, ASSIGNOR T0 THE B. F. GOODRICH COMPANY, OFNEW YORK, N. Y., A CORPORATION 0F NEW YORK.

TIRE-VULCANIZING APPARATUS.

Application lled August 9, 1913.

T0 all whom it may concern Be it known that I, JAMES D. TEW, a citizenof the United States, residing at Akron, in the county of Summit andState of Ohio, have invented certain new and useful Improvements inTire-Vulcanizing Apparatus, of which the following is a specification.

In vulcanizing pneumatic tire casings it is often necessary or desirableto employ a tubular air or water bag which furnishes an outward pressureAwithin the casing for the purpose of compacting, stretching or holdingthe shape of the casing during vulcanization, and with certain types inparticular, such as cord tires, the casing is originally smaller thanthe outer mold, and has considerable permanent stretch impartedrto it bythe inflatable bag. The bags have to be collapsed (as by means4 of avacuum pump) in order to `get them into the casings, and

after being used one or more times, they become rather stiff, andalthough still collapsible, they fail to contract to their` originalcross-section, the consequence being that a Wrinkle is formed in thebag, which seldom is completely efaced-by the distcntion of the bag, andthis wrinkle causes a corresponding ridge to appear on the inner surfaceof the vulcanized casing.

The-object of my invention is to substantially prevent the formation ofsuch ridges,

and this I accomplish by interposing a pressure-transmitting shieldbetween the pressure bag or tube and the tire casing, the said shieldbeing made of material which is sufciently stiff to avoid conforming tothe wrinkles or other small irregularities in the tube.

0f the accompanying drawings, Figure 1 represents a cross-sectionshowing a vulcanlzmg mold, tire-casing, tubular bag and a shieldconstructed according to my 1nvention, assembled in theiroperativerelation.

Specification of Letters Patent.

Patented Apr. 27, 1915.

Serial No. 783,927.

for connection with a source of fluid pressure or vacuum, these partsbeing of :familiar construction. l

In the mold is shown a tire-casing 14 of a Well-known cord type, andbetween said casing and the mold I have shown my improved shield 15. Thelatter may conveniently be made out of several plies of rubberizedfabric, shaped to conform to the inner contour of the tire andpreferably having its inner edges beveled. The ends of the shield arealso preferably beveled, and are 4adapted to overlap as indicated at 16when the shield is first placed in the tire.

In operating with this apparatus, the shield 15 is contractedcircumferentially and placed in the tire-casing 14, with its endsoverlapping as described, the tubular bag 12 is collapsed by exhaustingthe air from it with a vacuum pump, and is placed in the casing, thevacuum causing the side wall of the bag to assume the dotted-lineposition shown in Fig. 1. The ring 11 (which is in two or more sections)`is put in place and the mold parts assembled and bolted together in theusual way. The tire casing being initially smaller than the outer mold,it is eVident that when the bag 12 is inflated by means of hydraulic orother fluid pressure, its side wall, which had previously assumed thedotted-line'position, will not at once become fully convex, but willform a wrinkle 17 which gradually becomes smaller as the bag and casingexpand, but which usually does not entirely disappear, especially if thebag has been used several times. The presence of thelshield 15, however,prevents the formation ofa corresponding ridge on the inner surface ofthe casing when -the latter is fully expanded in the mold, as thematerial of which said shield is composed will be sufficiently stiff totransmit the outward pressure of the bag without conforming to theshallow wrinkle which ordinarily remains after the outer moldhasarrested further expansion. At the same time the shield is suflicientlyflexible to be inserted in the 100 tire and to take the natural contourimposed b y the mold and the bag, its endsbeing initiallyoverlapped bvan amount correspondlng to the circumferential expansion which theshield undergoes during the distention 105 of the bag and casing.

The term outer mold is intended to include any means used to confine theoutside of the. tire during vulcanization.

I claim Apparatus for stretching andvulcanizing pneumatic tire casingscomprising, in coinbination with the outer mold and inner inflatablepressure-tube, an annular, relativelystiff, but flexible,discontinuous,.removable shield adapted to be located between the tubeand the tire casing, for transmitting the pressure of the tube to thecasing Without substantially conforming to irregularities in the surfaceof said tube, said shield being longer than the unexpanded circumference15 of the pressure tube, so that its ends overlap when placed in thetire and slide on each other as the tire is expanded by inflation of thetube.

In testimony whereof I have hereunto set 2o my handin the presence oftwo subscribing witnesses, this sixth day of August, 1913.

JAMES D. TEW'.

IVitnesses:

L. A. SMITH, E. F. BAUER.

